Cooking with olive oil is a controversial subject with some people saying it is fine and others insisting it damages the oil. The truth falls somewhere in between, so if you prefer olive oil in your recipes, use the suggestions below as precautions to preserve nutrients.
Olives are one of the oldest foods known to man and are thought to have originated in Crete or Syria some 6000 years ago. The golden color of the rich oil pressed from tree-ripened olives has been consumed by healthy traditional cultures since as early as 3000 BC.
Olive oil especially the first Fall harvest known as Olio Nuovo is truly one of the crown jewels of fats and what I always buy.
Olive oil is primarily composed of oleic acid, which is monounsaturated fat. Monounsaturates are one of the three main categories of fats. The other two are saturated fats and polyunsaturated oils.
The three types of fats – do you know how to tell the difference?
Saturated fats like coconut oil and tallow, are extremely stable because they pack together tightly courtesy of very straight carbon bonds that are all occupied by hydrogen atoms. Â Saturated fats are solid or semisolid at room temperature and make ideal cooking fats because of the inherent stability provided by their chemical structure which means that they do not easily go rancid when heated during cooking or form the free radicals that contribute to heart disease and cancer.
Polyunsaturated fats do not pack together as tightly as saturated fats and hence are liquid at room temperature and remain so even if refrigerated.  The chemical structure of polyunsaturated oils is such that there are unpaired electrons for every carbon-carbon double bond which are highly reactive if heated or processed in any way. Even simple exposure to the air or light can cause rancidity in fairly short periods of time. Grapeseed oil is a fat that is extremely high in polyunsaturates.
Monounsaturated fats like olive, canola, and avocado oil are liquid at room temperature yet become semi-solid if refrigerated. Sesame oil has very similar levels of mono to polyunsaturated fat.
The single carbon-carbon double bonds which make up the chemical structure of monounsaturated fats do not pack together as tightly as saturated fats but are more tightly bound than those of polyunsaturated oils.
Monounsaturated fats do not go rancid as easily as polyunsaturated oils but are more delicate than saturated fats due to a slight molecular bend which is not as straight in shape as the carbon bonds in a fully saturated molecule.
Now that we understand the basic structure of the 3 types of fats, it is easy to identify the type of fat that primarily composes an oil as this can be ascertained by simply observing its form at either room temperature or when refrigerated.
If a natural fat is solid or semisolid at room temperature, then it is primarily saturated. If it is fully liquid at room temperature but goes solid in the refrigerator, it is primarily monounsaturated, and if it is liquid when either refrigerated or at room temperature, it is mostly polyunsaturated.
With proper identification of the kinds of fats now complete, let’s turn our attention to the proper cooking oils.
Cooking with what fats  – when?
It is clear that fats that are primarily saturated like tallow, coconut or palm oils are wonderful for cooking as the heat from cooking does not easily damage them or form free radicals.
On the other hand, polyunsaturated oils like sunflower, corn, grapeseed, soy or safflower should be strictly avoided for cooking as they are too easily damaged as those free electrons react too easily with heat or oxygen.
But what about monounsaturated fats, in particular, olive oil? This is where the issue gets a bit murky.
It is absolutely true that cooking with olive oil will not form trans fats. Even higher heat cooking with olive oil will not cause much free-radical creation although I would venture to say that there are certainly some free radicals formed when high heat cooking with monounsaturates due to the slightly less stable structure as compared with saturated fats.
I personally choose to avoid cooking with olive oil, especially extra virgin olive oil (EVOO). For one thing, good quality EVOO is quite expensive and should be properly packaged in dark-colored glass to protect the delicate nutrients. Studies have shown that light quickly degrades the quality of extra virgin olive oil.
Research shows that only two months’ exposure to light caused free radical increases in extra virgin olive oil to such a level that it could no longer be classified as extra virgin!
With light so easily damaging to extra virgin olive oil, it seems obvious that heat and cooking would damage it as well and studies bear this out. Heat as low as 350F (180C) can significantly damage the beneficial phenols in olive oil. Phenolic substances are highly anti-inflammatory in nature and likely an important reason why studies of the Mediterranean Diet which is high in olive oil have indicated a decrease in heart disease risk.
As a result, it seems prudent that even though cooking with olive oil does not produce any transfats or much free radical damage, it does reduce much of the beneficial aspect of consuming this healthy traditional oil in the first place.
Light saute cooking with olive oil at temperatures no higher than 200-250F seems to be safe and minimally damaging. However, oven baking or higher heat cooking on the stovetop with olive oil is not wise given that there are much hardier and less expensive fats to choose from like expeller-pressed coconut oil or palm oil!
By far, the best use of good quality, nutrient-loaded extra virgin olive oil is as a salad dressing. Combining one part vinegar or lemon juice with between 3-5 parts oil along with a drizzle of walnut oil and flavoring herbs of choice will provide a truly healthy topping for any salad or vegetable mix.
A Word of Caution for Olive Oil Lovers
While numerous studies have shown the beneficial effect of olive oil in the diet likely due to the anti-inflammatory nature of the phenols, it is advisable to go easy on this traditional fat if weight loss is your goal.
In 1994, the journal The Lancet published a study which noted that fat tissue is primarily composed of monounsaturated fat. Â Could this be a contributing reason for middle-age weight gain that is so common in Mediterranean countries (Eat Fat Lose Fat, p.70)?
The chemical structure of monounsaturated oils could be part of the problem. Â Monounsaturates like those found in olive oil are composed of longer chain fatty acids unlike the short and medium-chain fatty acids found in coconut oil, palm oil, butter, and other animal fats.
Short and medium-chain fatty acids are absorbed quickly and directly by the body for immediate energy whereas the longer chain fatty acids must be acted upon by bile salts to be digested. For this reason, longer chain fatty acids are more likely to contribute to weight gain.
Where to Find Quality Extra Virgin Olive Oil
It is important to realize that much of the conventional olive oil on the market isn’t even olive oil at all, according to Tim Mueller, an investigative journalist who has written a book on the subject called Extra Virginity: The Sublime and Scandalous World of Olive Oil.  If you suspect your olive oil is fake, put it in the refrigerator to see if it properly solidifies. Another test is to see if your extra virgin olive oil can keep a wick burning. Refined oils masquerading as extra virgin olive oil cannot typically hold a flame very well.
Unfortunately, neither of these tests can completely guarantee authenticity.
To be sure of the quality of your extra virgin olive oil, check this vetted source that comes directly from the olive oil farms themselves. These small farms are also working to preserve heirloom olive tree varieties being rapidly destroyed to make room for more corporate-friendly groves.
More Information
Extra Virgin Olive Oil Like You’ve Never Seen or Tasted Before
Traditional and Unusual Uses for Olive Oil
Liver and Gall Bladder Cleanse Using Olive Oil
Selecting a Healthy Cooking Oil and Reusing it Safely
The Truth About Pumpkin Seed Oil
Is Rice Bran Oil a Healthy Fat?
Caution When Using Chicken Fat for Cooking
How Vegetable Oils Make Us Fat
How Argan Oil Benefits Health
Red Palm Oil Benefits Rival Coconut Oil
Walnut Oil: Healthy Sub for Flax Oil
Picture Credit
Rebecca
Neat article. I have been using olive oil for baking, but recently switch to coconut oil. I think this is a wise change since the oil does add an odd flavor to baked goods.
Sarah, TheHealthyHomeEconomist
Yes, save that EVOO for salad dressings and light sautes only.
Kerri
Thank you so much for this.
Now elaborate on coconut oil. I have 2 jars in my house one is organic unrefined expeller pressed, says it is good for cooking only up to 280 degrees (medium heat). The other jar is organic refined expeller pressed reads it is good for cooking up to 360.
So, does this mean you should not be baking/cooking with unrefined expeller pressed coconut oil?
And do you know what (or where I can find an accurate list of temps). For example, what temp does a cast iron skillet at medium heat register at (does medium heat in this sense equate to medium heat mentioned above at 280 on the jar)? What heat does a stainless steel popcorn popcorn popper register at?
Just want to dot my i’s and cross my t’s here. 🙂 Thanks for all you do!!!!
Sarah, TheHealthyHomeEconomist
You can cook with virgin coconut oil just like expeller pressed coconut oil. You just will get a coconut-y flavor to your foods by doing this.
Shaniqua
I have an infrared thermometer that I use to measure the general temps of stuff like how hot a pan is.
Erika Ramos via Facebook
Thank you for this !!! It’s definitely something I’ve been wondering about ! I’d love it if there was a chart or post about what’s best for baking/sauteing/ stove top cooking (temp. included from 250 degrees up to 450 degrees-as with some bread baking) and for uncooked items so that all the information for uncooked, cooked, and temp. recommendations , substitution for milder flavor/best results/wallet friendly cooking/baking/uncooked mediums, as well as what’s best for what are all together which would answers everyone’s questions all in one page. That would be a valuable and convenient read !! Please consider it !!
Stephanie Renee Peña via Facebook
We don’t cook with it. We also have a source of REAL olive oil grown in the USA, fresh/cold pressed, and organic (been to the farm and got to watch them press and bottle it)…but I can’t tell you where or else too many ppl will buy it up and then there won’t be any left for me! lol.
Raquel
Hi Sarah, when you say animal fats are you referring to lard as well? I use it for cooking on the stove top and baking.
Thanks
Sarah, TheHealthyHomeEconomist
Lard is a great cooking oil too.
Melissa Gunther via Facebook
I agree with Rochelle. It’s only organic coconut oil for my family!!
Rochelle Ferguson via Facebook
I cook everything in organic coconut oil.
m1ssdiagnosis
Thank you for this article, Sarah. I wasn’t aware of this information regarding EVOO and have been using it exclusively for my marinating, sauteing, and stove top cooking as it is the only oil that is allowed on the strict anti-candida diet my toxicologist has me on due to being exposed to mold. The only one, that is, besides virgin coconut oil. So you can be sure I will be using the coconut oil in its place more often. However, I do have to point out that since June I have been using a lot more EVOO and have lost over 50lbs from the detox diet. So it cannot be too terrible for weight loss. I am eager to see if the weight loss, a happy byproduct of regaining my health, speeds up when I switch to coconut oil!
Ronita Lussier
What do you think of ghee?
Sarah, TheHealthyHomeEconomist
Love ghee!
H.S.
I’m not sure I agree with you on this. Arab descent here with Palestinian born husband–we also lived back home for four years. You speak alot about “sacred foods” from different cultures and for the Palestinian culture at least, olive oil is the biggie. People will not and do not buy their oil from the store, but actually go to the mountains to buy it in bug gasoline containers to see it and make sure it is good quality. And they cook with it. They don’t ever fry with it, but they stew with it and grill with it and roast with it. And they always have. People remember their grandmas frying with animal fats and semna (clarified butter), but olive oil has always used for both soups, breads, stews as well as cold. Now, one thing is that the older people do not trim their meat at all there (though the younger generation does) so maybe the saturated fat from the meat stabilizes the olive oil?
Shaniqua
I lived in Sevilla, Spain for 2 years and Spaniards drown everything in olive oil. A deep fryer was my first purchase when I moved there. It’s the only oil available in stores for cooking besides sunflower oil. Everyone there knows that you only use sunflower oil to stretch out your OO in the deep fryer sometimes if you are on hard times. (No house in Andalucia is not without a deep fryer filled with at least half OO)
BUT they make a huge distinction between EVOO and Olive Oil. Fresh pressed raw EVOO is for salads, and for pouring on bread raw with raw cured ham and/or fresh cheese. They’ll sometimes use EVOO to quickly fry an egg with butter but even then they pour raw oil on top of the egg after it’s been cooked. They use “olive oil dregs” for the deep fryer. Not the first or second raw presses. My guess is that this heavier oil is higher in the saturated fats, and more heat stable. In the country I’ve no doubt they will use animal fats in the deep fryer. OO is a lot thicker than the virgin stuff. This deep fryer oil is also usually changed on a regular basis. They never cut the fat off of meat and think butter is a health food. Now I understand how wise they were.
Bianca
Great reply. We Italians are very similar… in our culture Olive Oil is considred liquid Gold ! and yes, eating the fat on meats is also considered healthy..
I often bake with Olive Oil… here is a great recipe to try:
Venetian Carrot Cake recipe by Nigella Lawson..